Michigan State University
African Americans face a much higher risk—2.52 times greater—than Caucasian Americans of developing cognitive impairment, including dementia, later in life. A new study uncovers several reasons why.
Much of that racial disparity can be explained by childhood disadvantages, such as growing up poor and in the segregated South, and lower socioeconomic status in adulthood, particularly educational attainment, researchers say.
Surprisingly, health problems, such as heart disease and diabetes, and health behaviors, such as smoking and drinking, don’t account for much of the racial gap, says Zhenmei Zhang, associate professor of sociology at Michigan State University.
While the findings don’t fully explain blacks’ higher risk of cognitive impairment, they point to a strong need for policymakers to focus more on reducing racial gaps in socioeconomic resources over a lifespan, Zhang says. The study is published in the Journal of Health and Social Behavior.
“Social policies such as increasing educational resources in low-income communities, providing economic support to poor students and their families, improving graduation rates in high schools and colleges, and eliminating discrimination against blacks in the job market may significantly reduce racial disparities in cognitive impairment in later life.”
Dementia is not a specific disease. It’s an overall term that describes a wide range of symptoms associated with a decline in memory or other thinking skills severe enough to reduce a person’s ability to perform everyday activities. Alzheimer’s disease accounts for 60 to 80 percent of cases.Vascular dementia which occurs after a stroke, is the second most common dementia type. But there are many other conditions that can cause symptoms of dementia, including some that are reversible, such as thyroid problems and vitamin deficiencies, according to the Alzheimer’s Association.
Researchers analyzed survey data from 8,946 participants in the Health and Retirement Study. They collected the information in multiple waves over a 12-year period (1998-2010); participants were aged 65 or older at the start of the study.
Once the researchers took into account the various socioeconomic factors, which include childhood disadvantages, the odds ratio of cognitive impairment between blacks and whites—or the racial gap—was reduced considerably, from 2.52 to 1.45. That means socioeconomic factors explained a lot.
Cognitive impairment among the elderly is a growing problem—spending on dementia care alone exceeds $100 billion a year in the United States—but it hits blacks particularly hard. The Alzheimer’s Association has identified Alzheimer’s disease among blacks as an emerging public health crisis.
“As people live longer and longer, it becomes an even bigger issue,” Zhang says.
Other researchers from Michigan State and from the University of Texas are couauthors of the study, which was supported by the National Institutes of Health.